1. Field of the Invention
The present invention relates to a method for mounting generally circular or cylindrical components and, more particularly, concerns a method for mounting electronic components such as cylindrical heat sinks in electronic applications.
2. Description of the Related Art
The increasing miniaturization of electronics has resulted in the ability to fabricate increasingly complex devices. Anyone who is familiar with the circuit boards used in personal computers will recognize that a tremendous number of components have to be mounted on these boards. The components include such things as integrated circuits, discrete circuit components, wiring, and electromechanical devices such as fans, disk drives and the like. The assembly cost of manufacturing a printed circuit board has increased with the increased complexity of the printed circuit board. Further, the actual assembly task is complicated by the greater density of components on the board as there is less room to allow assemblers to correctly position components on the board. This can result in assemblers being less efficient or even misassembling the boards.
One particular problem that occurs during board assembly is that the assembler may over-tighten or over-torque a component that is being mounted on the board. This can result in the component or the mount for the component being damaged. When components or their mounts are damaged as a result of over-tightening, the overall cost of producing the boards is increased as oftentimes the components, the mounts or even the board has to be replaced. Consequently, there is a need for mounting procedures and mounting tools that will allow for components to be mounted on printed circuit boards in such a manner that the components or the mount are not damaged as a result of the mounting process.
One such tool for mounting components is known as a torque tool. A torque tool will torque a fastener, such as a nut or screw, to only a preset amount of torque. This reduces the likelihood of damage to a component or to the board as a result of over-tightening the fastener. While these torque tools are very well suited for attaching fasteners to a board at a desired degree of torque, many components in the electronics field are not attached to the board through the use of such well known fasteners. These types of components generally include integral attachment mechanisms such as threads and the like. Consequently, torque tools cannot be used for these types of components.
An example of one such component is a circular heat sink that is typically mounted on top of an integrated circuit. The circular heat sink is generally cylindrical in shape and includes an attachment mechanism such as threads. The circular heat sink is mounted to the top of an integrated circuit so as to be in thermal contact with the integrated circuit to thereby allow the heat generated by the integrated circuit to be radiated away. Typically, circular heat sinks are mounted to integrated circuits through the use of a bracket. The bracket is initially glued or otherwise attached to the outer casing of the integrated circuit and the bracket defines an opening through which a first end of the circular heat sink is threadably engaged. The assembler grasps the cylindrical heat sink, positions it in the bracket and then twists it so as to tighten it to the bracket.
The overall configuration of the circular heat sink generally precludes the use of well-known torque tools. Consequently, the assemblers of printed circuit boards often screw the circular heat sinks into the brackets by hand. This is a very imprecise way of mounting the heat sink as the assembler is generally not able to determine the extent to which the heat sink has been positioned in the bracket. Mounting the heat sink in the bracket by hand can result in either the brackets being broken when the assembler over-tightens the heat sink, or can result in the heat sink not being properly attached to the bracket and therefore functioning inefficiently.
Hence, there is a need for an apparatus or method of attaching electrical components, such as circular heat sinks, to printed circuit boards in a manner which reduces the likelihood of damage to the printed circuit board or the component and still ensures that the component is properly mounted on the printed circuit board. To this end there is a need for an apparatus for attaching electrical components to printed circuit boards in such a way that the printed circuit board will be attached to a desired degree of torque to the printed circuit board.